[Milsurplus] RE: CRT info needed

[david_jackson at agilent.com]

Roger:


The P7 on the end of the tube number was the phosphor type and is a Blue-White Short- Yellow Long persistence.  You get an intense but short burst of blue-white and then the afterglow was yellow for several seconds.  Generally used for RADAR but the P7 was also used with photographic cameras that were sensitive to blue and UV to record single shot events.  The P11 phosphor (blue short) was also used with cameras but was difficult to see because of the eye's low sensitivity in the blue region.  Watching one was a treat for about 3 minutes, then your eyes started hurting and headaches followed if you did it long enough.

 

Thanks,

Dave Jackson, WA4OBJ

________________________________

From: JACKSON,DAVID (A-Americas,ex1) 
Sent: Friday, August 11, 2006 12:48 PM
To: 'milsurplus at mailman.qth.net'
Subject: CRT info needed

 

Roger:

 

I can't specifically say what this tube was used in but I worked for Tektronix and dealt with their dual beam oscilloscopes.  

 

Before digital oscilloscopes, a "dual channel" scope really was a single crt gun switched between two different inputs, either switching back and forth (chop mode) while the trace was going across the screen or alternating first one channel then the other (alternate mode).  The problem was that you couldn't view two simultaneous events because either the switching times were too slow or you only could display one signal at a time.  

 

The dual gun CRT was developed so that one channel connected to one gun and the other connected to the other gun and you could view simultaneous events- neither switching or alternating was needed.  Essentially, you had two oscilloscopes in one package using a common CRT screen, generally, but not always, sharing a common time base.  They were very popular with the Atomic Energy folks.  Truly a single shot event if there ever was one- the repetition rate of atomic blasts is pretty long.  Lasers fit into this category as well.  Targeting lasers generally have a 10-20 pulse per second rep rate.  Not truly single shot but slow enough to qualify as one.

 

Take a look at the Tek 7844 if you can find the specifications

Thanks,

Dave Jackson, WA4OBJ
=======================================================

From: "Roger Basford" <roger at new-gate.co.uk>

Subject: [Milsurplus] CRT info needed

 

Hi,

 

Anyone have any info on the application of a 5BDP7 JAN-CDU Du Mont Labs Dual 

Gun CRT?

 

73,

 

Roger Basford, G3VKM - Norfolk, England